In addition to upbeat earnings reports from Google and SAP, PC shipment news was better than expected, and Facebook's announced US$1 billion acquisition of Instagram appeared to confirm expectations of a hot mergers and acquisition market this year.

Computer stocks on the Nasdaq exchange, however, closed down by 1.83 percent in aggregate Friday afternoon. The Nasdaq itself was down by 44.22 points to 3011.33, the S&P 500 was down by 17.31 points to 1370.26 and the Dow Jones Industrial Average was down 136.99 to 12,849.59. The declines erased an uptick in markets Thursday, and closed the week at a loss for U.S. stocks.

Market watchers ascribed the sell off Friday as a reaction to reports of the rising cost of insuring Spanish debt against default, which exacerbated concerns about Europe's financial health. After a strong first quarter, markets have fluctuated in the last two weeks, buffeted by reports about the economic health of both Europe and China -- two huge markets for consumer and IT products. China's annual economic growth slowed to 8.1 percent in the first quarter of 2012 from 8.9 percent in the previous quarter, the National Bureau of Statistics said on Friday.

The earnings season for tech nevertheless got off to a good start this week, though quarterly reports were not entirely free of problem issues.

SAP's preliminary report for the first quarter on Friday was not uniformly upbeat, but the company gave assurances that the current quarter would be strong. SAP said first quarter revenue was up year-over-year by 11 percent to €3.35 billion (US$4.4 billion),while operating profit rose 6 percent to €630 million. The company's operating margin, however, slipped to 18.8 percent from 19.7 percent a year earlier.